#include<stdio.h>

int SumToNum(int start,int end)
{
  int sum = 0;
  for(int i=start;i<end;i++)
  {
    sum+=i;
  }

  return sum;
}

int main()
{
  int start = 1;
  int end =100;
  int sum = SumToNum(start,end);

  printf("sum = %d\n",sum);
}
